Solve the problem.
-The water acidity in a pool is considered normal when the average pH reading of three daily measurements is greater than 7.2 and less than 7.8. If the first two pH reading are 7.28 and 7.88, find the range of pH values for
The third reading that will result in the acidity level being normal.
A) 7.64

Question

Solve the problem.
-The water acidity in a pool is considered normal when the average pH reading of three daily measurements is greater than 7.2 and less than 7.8. If the first two pH reading are 7.28 and 7.88, find the range of pH values for
The third reading that will result in the acidity level being normal.
A) 7.64 < x < 9.44
B) 7.2 < x < 7.8
C) 6.44 < x < 8.24
D) 7.04 < x < 8.84

Quizplus · Accepted Answer

To ensure the average pH is between 7.2 and 7.8, we calculate the total pH needed across all three readings for both limits. For the lower limit: $3 \times 7.2 = 21.6$, and for the upper limit: $3 \times 7.8 = 23.4$. Subtracting the sum of the first two readings from these totals gives the range for the third reading. For the lower limit: $21.6 - (7.28 + 7.88) = 6.44$, and for the upper limit: $23.4 - (7.28 + 7.88) = 8.24$. Therefore, the third reading must be between 6.44 and 8.24.

Solve the Problem. -The Water Acidity in a Pool Is Considered Normal When